Estimate energy demand (Gross Energy) - Tier 2 — estimate_energy

Calculate gross energy (GE) intake per IPCC 2019 Tier 2 equations (Vol 4, Ch 10). Estimates net energy components for maintenance, activity, lactation, work, pregnancy, growth, and wool, then derives total gross energy using the REM/REG ratio approach from IPCC Eq 10.16.

All coefficients come from internal package data.

Usage

estimate_energy_demand(data, method = "ipcc2019")

Arguments

data: A dataframe with columns species, cohort, heads, and optionally iso3. Optional production columns: weight, milk_yield_kg_day, fat_percent, weight_gain_kg_day, work_hours_day, pregnant_fraction, temperature_c, diet_quality, grazing_distance_km, system.
method: Method for calculation (default "ipcc2019").

Value

Dataframe with added gross_energy (MJ/day), intermediate net energy components, and method_energy tracking column.

Examples

tibble::tibble(
  species = "Dairy Cattle", cohort = "Adult Female",
  heads = 100, weight = 600, diet_quality = "High",
  milk_yield_kg_day = 20
) |>
  estimate_energy_demand() |>
  dplyr::select(species, cohort, heads, ne_maintenance,
    ne_activity, ne_lactation, ne_growth, gross_energy)
#> # A tibble: 1 × 8
#>   species      cohort    heads ne_maintenance ne_activity ne_lactation ne_growth
#>   <chr>        <chr>     <dbl>          <dbl>       <dbl>        <dbl>     <dbl>
#> 1 Dairy Cattle Adult Fe…   100           46.8        7.96         61.8         0
#> # ℹ 1 more variable: gross_energy <dbl>